1. Field of the Invention
The present invention relates to a fluid structure control device which is applicable to an actuator, a fluid viscosity controller, a fluid valve, or the like. More specifically, the present invention relates to a fluid structure control device utilizing induced-charge electro-osmosis.
2. Description of the Related Art
Micro-pumps utilizing electro-osmosis are used in the technical fields of μ-TAS (micro-total analysis system) and the like owing to the simple structure thereof having no moving parts and the ease of installation in a micro-sized flow channel.
Recently, micro-pumps utilizing induced-charge electro-osmosis are attracting attention owing to possibility of achieving a high flow rate of liquid, possibility of AC driving to inhibit a chemical reaction between electrode and a liquid, and so forth.
U.S. Pat. No. 7,081,189 (hereinafter referred to as Document-1) discloses two types of pumps (1) and (2) utilizing induced-charge electro-osmosis: (1) a half coat type ICEO pump which has a metal post placed between a pair of electrodes, wherein the metal post is coated half with a thin dielectric film, thereby limiting the region of electric charges induced in the metal post to control the flow of a liquid; and (2) an asymmetric metal post-shape type ICEO pump which has a metal post in a triangular or like asymmetric shape between a pair of electrodes to control the liquid flow in one direction.
S. Gangwal, O. J. Cayre, M. Z. Bazant, and O. D. Velev: Phys. Rev. Lett., 100, 058302 (2008) (hereinafter referred to as Document-2) discloses displacement of polystyrene particles coated partially with a gold film perpendicularly to an electric field.
T. C. Halsey, and W. Toor: Phys. Rev. Lett., 65, 2820 (1990) (hereinafter referred to as Document-3) discloses displacement of dielectric particles by utilizing polarization (dipole) induced in the dielectric particles upon application of a voltage to the particles in a non-conductive solvent.